In the operation of machine tools such as punch presses and screw machines, the turning on and turning off of switches and valves often relate to the rung ladder programs previously used to operate the relays associated with prior controllers for such devices. This insures correct operation of the machine tool from an initial reset condition to the proper position to perform its operation at a proper time and location. Stating the matter in a negative sense, this prevents a machine such as a punch press from attempting to stamp a part from a tray that normally would be clear of the tool.